We present a formal system, E, which provides a faithful model of the proofs in Euclid's Elements, including the use of diagrammatic reasoning.

The role of audiences in mathematical proof has largely been neglected, in part due to misconceptions like those in Perelman and Olbrechts-Tyteca which bar mathematical proofs from bearing reflections of audience consideration. In this paper, I argue that mathematical proof is typically argumentation and that a mathematician develops a proof with his universal audience in mind. In so doing, he creates a proof which reflects the standards of reasonableness embodied in his universal audience. Given this framework, we can better understand (...) the introduction of proof methods based on the mathematician’s likely universal audience. I examine a case study from Alexander and Briggs’s work on knot invariants to show that we can fruitfully reconstruct mathematical methods in terms of audiences. (shrink)

Modern empiricism has been conditioned in large part by two dogmas. One is a belief in some fundamental cleavage between truths which are analytic, or grounded in meanings independently of matters of fact, and truth which are synthetic, or grounded in fact. The other dogma is reductionism: the belief that each meaningful statement is equivalent to some logical construct upon terms which refer to immediate experience. Both dogmas, I shall argue, are ill founded. One effect of abandoning them is, as (...) we shall see, a blurring of the supposed boundary between speculative metaphysics and natural science. Another effect is a shift toward pragmatism. (shrink)

Abstract: Chomsky (1986) has claimed that the prima facie incompatibility between descriptive linguistics and semantic externalism proves that an externalist semantics is impossible. Although it is true that a strong form of externalism does not cohere with descriptive linguistics, sociolinguistic theory can unify the two approaches. The resulting two-level theory reconciles descriptivism, mentalism, and externalism by construing community languages as a function of social identification. This approach allows a fresh look at names and definite descriptions while also responding to Chomsky's (...) (1993, 1995) challenge to articulate an externalist theory of meaning that can be used in the scientific investigation of language. (shrink)